Sofa



FIG. 1 is a front perspective view of a sofa, showing my new design, and including two pillows which are shown herein and throughout by way of example and form no part of the claimed design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a front elevation view thereof;

FIG. 5 is a side perspective view thereof taken from the right of FIG. 4;

FIG. 6 is a side perspective view thereof taken from the left of FIG. 4; and,

FIG. 7 is a rear elevation view thereof. 

I claim, the ornamental design for a sofa, as shown and described. 